Definition of Board certified

Board certified: Board certified in medicine means a physician has taken and passed a medical specialty examination.

Board eligible, by contrast, means that a physician has completed the requirements for admission to a medical specialty board examination but has not taken and passed the examination.

For example, a physician must do 3 years of training in an approved pediatric residency to be board eligible and then successfully complete a comprehensive written examination to be certified by the American Board of Pediatrics.

Definition of Babesiosis

Babesiosis: An illness caused by the parasite Babesia which is transmitted from animals to humans by ticks. In the US, it is typically contracted in the Northeast or Midwest -- in southern New England or New York State and in Wisconsin or Minnesota. The signs and symptoms include fever, chills, sweating, myalgias (muscle aches), fatigue, hepatosplenomegaly (enlargement of the liver and spleen) and hemolytic anemia (anemia due to break-up of red cells). Symptoms typically occur after an incubation period of 1 to 4 weeks and can last several weeks. The disease is more severe in patients who are immunosuppressed, splenectomized (lack their spleen), or elderly. It can cause death. Treatment involves antibiotics, usually clindamycin and quinine.

The parasite: While more than 100 species of Babesia have been reported, only a few have been identified as causing human infections. Babesia microti and Babesia divergens have been identified in most human cases, but variants (considered different species) have been recently identified. Little is known about the occurrence of Babesia species in malarial areas where Babesia can easily be misdiagnosed as Plasmodium (the agent of malaria).

The life cycle of the parasite: (This contains some technical information.) The B. microti life cycle involves two hosts, which includes a rodent, primarily the white-footed mouse, Peromyscus leucopus. During a blood meal, a Babesia-infected tick introduces sporozoites into the mouse host. Sporozoites enter erythrocytes and undergo asexual reproduction (budding). In the blood, some parasites differentiate into male and female gametes although these cannot be distinguished at the light microscope level. The definitive host is a tick, in this case the deer tick, Ixodes dammini (I. scapularis). Once ingested by an appropriate tick, gametes unite and undergo a sporogonic cycle resulting in sporozoites. Transovarial transmission (also known as vertical, or hereditary, transmission) has been documented for "large" Babesia spp. but not for the "small" babesia, such as B. microti.

Humans enter the cycle when bitten by infected ticks. During a blood meal, a Babesia-infected tick introduces sporozoites into the human host. Sporozoites enter erythrocytes and undergo asexual replication (budding). Multiplication of the blood stage parasites is responsible for the clinical manifestations of the disease. Humans are, for all practical purposes, dead-end hosts and there is probably little, if any, subsequent transmission that occurs from ticks feeding on infected persons. However, human to human transmission can occur through blood transfusions.

Deer are the hosts upon which the adult ticks feed and are indirectly part of the Babesia cycle as they influence the tick population. When deer populations increase, the tick population also increases, thus heightening the potential for transmission.

The diagnosis: Diagnosis can be made by microscopic examination of thick and thin blood smears stained with Giemsa. Repeated blood smears may need to be examined to make the diagnosis. Antibody detection by indirect fluorescent antibody (IFA) test is a complementary diagnostic test. Isolation of Babesia by inoculation of the patient's blood into hamsters or gerbils may also assist in diagnosis. Animals inoculated with infective blood typically develop parasitemia (parasites circulating in their bloodstream) within 1 to 4 weeks.

Treatment: The current drug treatment options (in 2002) are clindamycin plus quinine or with atovaquone plus azithromycin. Exchange transfusions have been used in severely ill patients with high parasitemia (high levels of the parasite in the blood).

Definition of B virus

B virus: An infectious agent commonly found among macaque monkeys, including rhesus macaques, pig-tailed macaques, and cynomolgus monkeys. Monkeys infected with this virus usually have no or mild symptoms. In humans, however, B virus infection can result in a fatal encephalomyelitis. B virus disease in humans is extremely rare, but often fatal -- an estimated 80% of untreated patients die of complications associated with the infection.

Persons at greatest risk for B virus infection include veterinarians, laboratory workers, and others who have close contact with Old World macaques or monkey cell cultures. Infection is typically caused by animal bites, scratches, or exposure to the tissues or secretions of macaques. The virus is also known as Cercopithecine herpesvirus

Definition of IBS (irritable bowel syndrome)

IBS (irritable bowel syndrome): A common gastrointestinal disorder involving an abnormal condition of gut contractions (motility) characterized by abdominal pain, bloating, mucous in stools, and irregular bowel habits with alternating diarrhea and constipation, symptoms that tend to be chronic and to wax and wane over the years. Although IBS can cause chronic recurrent discomfort, it does not lead to any serious organ problems.

Making the diagnosis usually involves excluding other illnesses. Treatment is directed toward relief of symptoms and includes changes in diet (eating high fiber and avoiding caffeine, milk products and sweeteners), exercise, relaxation techniques, and medications.

Also called spastic colitis, mucus colitis, nervous colon syndrome.

Definition of Basilar

Basilar: Located at or near the base of a structure, especially the base of the skull.

For example, a basilar fracture is a break in the bone at the base of the skull and can be life-threatening

Definition of B cell

B cell: A type of white blood cell and, specifically, a type of lymphocyte.

Many B cells mature into what are called plasma cells that produce antibodies (proteins) necessary to fight off infections while other B cells mature into memory B cells.

All of the plasma cells descended from a single B cell produce the same antibody which is directed against the antigen that stimulated it to mature. The same principle holds with memory B cells. Thus, all of the plasma cells and memory cells "remember" the stimulus that led to their formation.

The maturation of B cells takes place in birds in an organ called the bursa of Fabricus. B cells in mammals mature largely in the bone marrow.

The B cell, or B lymphocyte, is thus an immunologically important cell. It is not thymus-dependent, has a short lifespan, and is responsible for the production of immunoglobulins. It expresses immunoglobulins on its surface.